Fix Issue 15909 - Duplicate case error reports characters as numbers

[Luhrel]

No description provided.

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Bugzilla references

Auto-close	Bugzilla	Severity	Description
✓	15909	trivial	Duplicate case error reports characters as numbers

Testing this PR locally

If you don't have a local development environment setup, you can use Digger to test this PR:

dub run digger -- build "stable + dmd#11716"

[Luhrel]

The problem was that the CaseSatement is casted to the type of the expression in the switch statement, which is promoted as an integer via integralPromotions.

[MoonlightSentinel]

Otherwise LGTM

Doesn‘t use cs.exp.type anymore

[MoonlightSentinel]

Rebased it for you, that should make BuildKite pass again.

[Luhrel]

Rebased it for you, that should make BuildKite pass again.

Oh, thanks !